Why do it get parent.childElementCount as undefined
I am teaching myself some Javascript and don't understand why Chrome console tells me this when I try it out at the Google homepage:
parent
> DOMWindow
parent.childNodes
> undefined
parent.frames[0].childElementCount
> undefined
parent.frames.length
> 1
parent.frames[0].name
> "wgjf"
parent.wgjf.childElementCount
> undefined
parent.frames[0].childElementCount
> undefined
parent.childElementCount
> undefined
I do notice that there are frames, and the parent has child nodes, so why all these u开发者_C百科ndefined?
I would like to teach myself to the point that I can figure out how clicking on a username in the gmail chat window on the left opens up a chat window on the right - I should be able to trace the list of function calls that makes this happen
childNodes is a property of DOM-nodes, a window-object is not a DOM-Node.
Try:
parent //window-object
.document //document-object
.documentElement //root-node, usually <html>
.childNodes // usually <head> and <body>
like suggested by casablanca.
(should return 2 for a valid HTML-document)
加载中,请稍侯......
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